• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.293-299
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• 2020

The characteristics of the polycarbosilane (PCS)-based composite ceramic layer was studied by controlling the curing temperature. The stress at the interface of the graphite and SiOC composite layer was evaluated v ia finite element analysis. As a result, the tensile stress was released as the carbon ratio of the SiC decreases. In experiment, the SiOC layers were coated on the VDR graphite block by dip-coating process. It was revealed that the composition of Si and C was effectively adjusted depending on the curing temperature. As the solution-based process is employed, the surface roughness was reduced for the appropriate PCS curing temperature. Hence, it is expected that the cured SiOC layer can be utilized to reduce cracking and peeling of SiC ceramic composites on graphite mold by improving the interfacial stress and surface roughness.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.207-207
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• 2009

요업 소성로에서 내화재로 흡수된 에너지는 피가열물에 방사열로 작용하며, 이때 내화물의 방사율이 높을수록로내의 온도를 상승시켜 소비되는 연료가 절감된다. 따라서 내열성과 방사율이 높은 세라믹 내열도료를 개발하여 구성물의 결정 구조, 열적특성, 적외선 방사량 및 에너지 절감실험에 대한 데이터를 분석한 결과 높은 내열성과 적외선 방사량 증가에 따른 에너지 절감에 효과가 있음을 알 수 있었다.

• Journal of the Korean Ceramic Society
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• v.38 no.4
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• pp.319-324
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• 2001

본 연구에서는 NaOH로 첨착시킨 활성탄의 표면특성변화와 H$_2$S 흡착능을 고찰하였다. 첨착시약으로 사용된 NaOH 용액의 농도는 1~8N이며, 활성탄의 입자크기는 8$\times$30mesh가 적용되었다. 실험결과는 첨착율이 0.87~5.8% 범위 내에서 증가할수록 BET 표면적은 1050$m^2$/g에서 783$m^2$/g로 감소하며, 표면산도는 0.541meq/g-AC에서 0meq/g-AC으로 감소하고, pH는 9.56에서 10.86으로 증가하는 것으로 밝혀졌다. 또한 NaOH로 첨착시킨 활성탄의 H$_2$S 평형흡착능을 보임으로써 비첨착활성탄에 비해 2~3배 높은 수준을 나타냄을 알 수 있었다.

• Journal of the Korean Ceramic Society
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• v.38 no.1
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• pp.28-33
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• 2001

WC-6%Co 소결체를 열처리할 때 발생하는, 시편 표면에서의 급격한 입자 성장 거동을 열처리 분위기를 변수로 하여 관찰하였다. 열처리 분위기로 수소와 메탄을 각각 사용하였고, 온도는 1400~145$0^{\circ}C$, 압력은 1~3 Torr, 그리고 시간은 100분까지 변화시켰다. 표면에서의 입자 성장은 수소 분위기보다 메탄 분위기를 사용하는 경우 훨씬 빠르게 일어났다. 그리고 열처리 온도가 증가할수록, 압력이 감소할수록 입자 성장 속도가 증가하였다. 이때 성장한 입자의 크기 분포는 비정규 분포를 보였다. 한편, 입자 성장은 열처리시 증발하는 시편의 Co 무게 감소와 밀접한 관계를 보였다. 이러한 표면에서의 입자 성장 현상을 열처리한 조건과 관련되어 WC-Co 상태도에서 예측할 수 있는, 탈탄-탄화 반응 및 비정상 입자 성장 현상 관점으로 설명하였다.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.1021-1026
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• 2003

Resin impregnation of carbon materials was affected by surface of carbon materials. The surface of carbon materials with coupling treatment improved comparability and wettability with resin, and that increased impregnation efficiency and properties of carbon materials. As a results of FT-IR, The silanol was coated on carbon surface with one layer. Coupling treatment of carbon materials increased impregnation efficiency, which improved porosity, mechanical strength, density and friction behavior.

• Journal of the Korean Ceramic Society
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• v.39 no.12
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• pp.1177-1182
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• 2002

Highly surfaced and porous hydroxyapatite body was artificially formed on the surface of a shell through a reaction with phosphatic solutions. As a result of qualitative observation, hydroxyapatite seemed to be crystallized by solution-precipitation process accelerated by the nucleation surface of a shell. The process of formation of hydroxyapatite layer was as follows. 1. Dense nucleation and growth on the surface of solid phase 2. Formation of microporous layer by contact and entanglement between crystallines 3. diffusion of solution through the porous layer and thickness growth of layer towards inside

• Journal of the KSME
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• v.57 no.1
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• pp.52-56
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• 2017

금속, 세라믹, 고분자 등 다양한 소재에 적용이 가능한 고출력 광에너지인 레이저 기반의 마이크로-나노스케일 표면가공기술의 기본 원리 및 응용 분야를 소개한다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2002.05a
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• pp.10-11
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• 2002

• Ceramist
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• v.5 no.2
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• pp.37-43
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• 2002

• The Journal of the Korea Contents Association
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• v.10 no.11
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• pp.243-250
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• 2010

The bonding strength and color reproducibility of titanium-ceramic prosthesis were analyzed the effect according to the surface treatments of titanium and the glazing temperatures of the low fused porcelain. The result of bonding strength compared with respect to the surface treatments was observed that the STB1 group coated by TiN had strongest boding strength and then came the SB1 group used special bonding agent, the SGB1 group coated by gold in that order. The bonding strength by the glazing temperature was indicated that the group with $770^{\circ}C$ of glazing temperature was observed increasing the bonding strength as compared with it of the other group, and the group with $810^{\circ}C$ of glazing temperature was observed to be decreased the bonding strength. Glazing temperature increases, the color by the surface treatment of titanium influenced the color of titanium-ceramic on account of getting higher brightness(${\Delta}L$). As a this result, the SB1 and SGB3 groups was evaluated to has the best color reproducibility.